The present invention relates to a semiconductor module and an inverter device.
There exists an inverter circuit for driving an electric machine of a hybrid vehicle, an electrical vehicle, or the like. A semiconductor module, which includes switching elements that structure the inverter circuit, generates a large amount of heat, and furthermore, requires downsizing. To attain this, frequently a water-cooled system is used as a cooling structure for the semiconductor module. As an example of a structure for such a water-cooled system, Japanese Patent Application JP-A-2004-349324 (pages 6 and 7, and FIG. 5) discloses the structure that is shown in FIGS. 15A, 15B, and 15C. In this figure, FIG. 15A is a plane view, FIG. 15B is a side view, and FIG. 15C is a front view. The semiconductor module 101 that is shown in this figure is provided with a base plate 102 having stripe-shaped fins 103 formed on the back surface thereof and six substrates 104 that are mounted on the upper surface thereof. In addition, on the lower surface of the base plate 102, a water path cover (not illustrated) is provided so as to be in contact with the bottom surface of the fins 103 (the surface below the fins 103 in FIG. 15B), and thereby, respective water flow paths 105 are formed between the plurality of fins 103. Therefore, in this semiconductor module 101, the coolant flow direction D is in the longitudinal direction (the left to right direction in FIG. 15B) of the base plate 102. In addition, the six substrates 104 that are mounted on the base plate 102 are disposed in a row in the coolant flow direction D.
In addition, two elements, that is, IGBTs (Insulated Gate Bipolar Transistor), which serve as switching elements 106, and diode elements 107, are arranged in each of the substrates 104. In addition, connection terminal areas 108, where the wire bonding for electrically connecting the elements 106 and 107 on each of the substrates 104 with a control substrate (not illustrated) is carried out, is disposed adjacent to each of the substrates 104. In addition, on these substrates 104, one each of two switching elements 106 and two diode elements 107 are disposed so as to be alternately arranged side-by-side in a direction that is perpendicular to the coolant flow direction D. In addition, the connecting terminal areas 108 are arranged in the sides that are opposite to the sides at which a pair of substrates 104A and 104B faces each other in the coolant flow direction D.